Drill-gage and countersink.



1. M. DUNLAP. DRILL GAGE AND COUNTERSINK. APPLICATION FILED FEB. 12,191B.

1 ,279,302. v Patented Sept. 17, 1918.

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2 3/? iii/ JESSE'M. DUNLAP, OF LITTLE ROCK, ARKANSAS.

DRILL-GAGE AND COUNTERSINK.

Specification of Letters Patent. Patent ui Sept, 17, 1918,

Application filed February 12, 1918. Serial 'No. 216,730.

To all whom it may concern:

'Be it known that I, Jnssn M. DUNLAP, a citizen of the United States,residing at Little Rock, in the county of Pulaski and State of Arkansas,have invented certain new and useful Improvements in Drill-Gages andCountersinks, of which the following is a specification.

This invention relates to new and useful improvements in drills, and theprimary object of the invention is to provide a new and improved type ofdrill, that is slidably mounted within a holder and which is providedwith'means for locking said drill in various adjusted positions, wherebythe projecting portion thereof may be varied according to the depth ofthe hole desired. 1

Another object of the invention is to provide a'device of thischaracter, which is provided with a holder having an adjustable drillmounted therein provided with means whereby its length may be varied,and a countersink attachment formed on the lower end of the drill, thatforms the countersink at the same time that the hole is being bored. Afurther object of the invention is to provide'a device of this characterwhich is easily and simply constructed, inexpensive to manufacture, andone which will be very efficient in operation.

With these and numerous other objects in view, my invention consists ofthe novel features of construction, combination and arrangement of partswhich will be herein referred to and more particularly pointed out inthe specification and claims.

In the accompanying drawings:

Figure 1 is a side elevation of my new and improved drill with theattachment,

Fig. 2 is a similar view taken at right angles to the first view,

Fig. 3 is a horizontal section through the drill Fig. 4 is a verticalsection through the lower portion of the drill showing the means fordetachably connecting the drill with, its engaging member, and

Fig. 5 is a bottom plan view of the device.

In describing my device, I shall refer to the drawings in which similarreference characters designate corresponding parts throughout theseveral views.

The numeral 1 designates a tubular holder which has positioned in theupper end thereof the conventional type of connecting means 2, which isordinarily employed in drills of this character. The lower end of theholder 1 is enlarged, and tapered or cone shaped as shown at 3, thesurface of the tapered portion being provided with screws 4 at oppositepoints, which have one edge thereof 5 forming a cutting edge. The I.

extremity of the lower end of the groove is opened, so as the drill 6may be mounted therethrough. Extending longitudinally along the holder 1and projecting from the inner surface thereof, is alongitudinallyextending rib 7 for a purpose to be hereinafter described.The holder 1 is provided with a longitudinally extending slot 8' throughwhich the fastening means of the drill proj ect.

Slidably mounted within the holder 1 is a drill engaging member 9 whichhas an open lower end 10 that is stepped as shown at 11, andv which isadapted to receive the upper end of the drill 12. This drill projectsthrough the bottom of the holder, and is provided on opposite sides withlongitudinally extending grooves 13 as is common to this type of device.The drill is detachably held within the holder 9, by means of a spring 11 that is secured within this countersunk portion in the lower outerface of the holder'9, and which has its lower extremity bent laterallyas shown at 15 and adapted to be positioned in a groove 16 in the drill.By this means the drill will be securely held in the holder, but ifdesired it may bedetached therefrom.

The opposite faces of the holder adjacent the slot 8 at the lower endthereof are provided with teeth 17 and secured to the portion of theholder 9' that alines with the slot 8 is a fiat spring 18, which has itslower end extending outwardly through the slot, and enlarged byprojecting laterally at each side as shown at 19, said projectingportion being adapted for engagement with the teeth 17 to lock the drillengaging member in various adjusted positions.

When the various parts of this drill are assembled, as clearly shown inFigs. 1 and 2 of the drawings, the grooves in the drill 13 ceive theconventional type of drill head,

justed according to the depth of the hole desired to be drilled. Thisadjustment is easily made, by shifting the'spring agent 18 and movingthe holder, and consequentlythe drill to the desired position, whereuponupon releasing the spring the same will automatically engage with theteeth and any upward movement of the drill will be prevented. The drillis easily detachable from the holder, as the connection 2 at the top ofthe holder is removable, and the drill engaging member and drill may betakenifrom the and to connect with various types.

From the foregoing description of the construction, operation andadvantages of my invention, it is thought that a clea'rand comprehensiveunderstanding of the construction and advantages of this device will be,had, and while I have described and shown a specific device, I desirethat it be understoodthat such changes may be made i in said structureas do not depart from the spirt andscope of the invention as claimed.

Copies of this patent may be obtained for Having fully described myinvention, what I claim is new, and desire to secure by Letters Patent,is:

1 A device of the class described including a tubular holder, a drillextending through the lower end of said holder, a drill engaging memberslidably mounted within said holder, said holder having a longitudinallyextending slot therein, teeth adjacent the opposite edges of said slot,a spring member carried by said holder and projecting through the slot,and lateral extensions on the lower end of said spring engageable 'withsaid teeth to prevent upward move- .mcnt 0f the drill, but permittingits adjustmentwhen said member is disengaged from the teeth.

I '2. A device of the class described including -a tubular holder, adrill extending through the lower end thereof, a drill engaging memberslidably mountedwithin said holder, means for detachably connecting thedrill with themember,=a longitudinally extending slot. in said holder,means carried by the drill engaging member projecting through said slotfor engaging the outer face of the holder to lock said member in variousadjusted positions, and a countersink means formed on the lower endofsaid holder.

In testimony whereof I aiiix my signature hereto.

Jesse M. DUNLAP.

flve cents each, by addressing the Commissioner of, Patents,

Washington, I). 0.

